Leviticus 27:26
"'Surely no man may consecrate a firstborn that already belongs to the Lord as a firstborn among the animals; whether it is an ox or a sheep, it belongs to the Lord.
Exodus 13:2
"Set apart to me every firstborn male -- the first offspring of every womb among the Israelites, whether human or animal; it is mine."
Exodus 13:12-13
then you must give over to the Lord the first offspring of every womb. Every firstling of a beast that you have -- the males will be the Lord's.
Exodus 22:30
You must also do this for your oxen and for your sheep; seven days they may remain with their mothers, but give them to me on the eighth day.
Numbers 18:17
But you must not redeem the firstborn of a cow or a sheep or a goat; they are holy. You must splash their blood on the altar and burn their fat for an offering made by fire for a pleasing aroma to the Lord.
Deuteronomy 15:19
You must set apart for the Lord your God every firstborn male born to your herds and flocks. You must not work the firstborn of your bulls or shear the firstborn of your flocks.